1. Field of the Disclosure
This disclosure relates generally to multi-zone completion apparatus and methods for production of hydrocarbons from subsurface formations.
2. Background of the Art
For fracturing, gravel packing and production from a multi-zone well, a completion assembly containing an outer assembly and an inner assembly are used to perform treatment operations, including fracturing and gravel packing (frac/pack or frac/packing) and flooding or injection operations in each zone before producing the hydrocarbons (oil and gas) from such zones. The outer assembly includes a top packer, a bottom packer and an isolation packer for each zone. To treat a particular zone, such zone is isolated from other zones by setting the packers. A cross-over (also referred to as frac port) in the inner assembly is aligned with a flow port in the outer assembly. A treatment fluid (typically a mixture of water, proppant and additives) is supplied under pressure into the inner string, which treatment fluid flows from the frac port to the formation via the flow port. At times the proppant packed around the frac port can cause the inner string to become stuck in the outer string. To remove the outer string, the inner string is cut off at or above the stuck location. The outer string is then retrieved.
The present disclosure provides apparatus and method for installing and retrieving a multi-zone completion assembly in wellbores.